The author`s interest in south-eastern Europe was first aroused in 1954 when, as un undergraduate, he studied the geography of the area. He has subsequently made several visits to the former Jugoslavia and Greece, in order to work on the coins in museums in Athens, Corinth, Ljubljana, Thessaloniki, and Zagreb. The present work originated in an essay which was awarded the Society`s Parkes Weber Prize in 1955. From it, there grew a Ph.D. thesis at Cambridge. Then, was published as a book under the title Coinage in the Balkans, 820-1355, by the Institute for Balkan Studies (Thessaloniki, 1965). The edition was exhausted in 1966, and the book was `pirated` in the United States. After that the text had been extensively re-written and expanded, to take account of the hundreds of new books, articles and hoard-reports; its scope had also been extended, to deal with the second half of the fourtheenth century, and with Wallachia; so, a second revised edition emerged under the slightly changed title, Coinage in South-Eastern Europe, 820–1396 (Royal Numismatic Society, London, 1979). To the current third edition a new extensive introduction and an Appendix have been added, while the new bibliographical references have been incorporated into those of the previous editions; so far as it concerns the main text, this edition exactly reproduces that of 1979, except that a few spelling errors have been silently corrected. South-eastern Europe emerged from the migration period with a money economy restricted essentially to Constantinople. During the ninth century the use of a large-scale petty currency, as well as of gold and silver coinage, was restored in central Greece, and by the millenium, Byzantine copper folles were minted in remarkably large quantities, running into hundreds of millions. The spread of the money economy into the interior, however, proceeded only slowly until about the end of the twelfth century . From then on, a wide range of different coinages were used in south-eastern Europe, including Venetian, Hungarian, Bulgarian, Serbian, Bosnian, and Slavonian, the crusader issues of Frankish Greece, and coins from the cities of the Adriatic coasts, such as Kotor, Split, and Dubrovnik (Ragusa). The evidence of archaeological excavation and of several hundred coin-hoards is explored, in an attempt to assess the commercial, military, and other uses of money on pre-Ottoman times.